In a typical balancing machine for balancing a rotary member such as a motor vehicle wheel, the rotary member or wheel is mounted on a balancing machine main shaft, which is rotated by an electric motor. Any imbalance in the rotary member is ascertained by an imbalance measuring run during which the main shaft with the rotary member is rotated by the electric motor.
When the main shaft is stopped, the main shaft or the rotary member generally is not disposed in the appropriate position whereby compensation of the imbalance of the rotary member can be achieved. Correcting the imbalance is typically accomplished by fitting a balancing weight to the rotary member. When balancing a wheel it is desirable that the wheel clamped to the main shaft be moved into a specific position, referred to as the balancing angular position, such that the position on the motor vehicle wheel to which a suitable balancing weight is to be fitted is disposed perpendicularly above the main shaft, that is to say in the 12 o'clock position. This position is called the easy balancing position because the balancing operator has ready access to the point on the vehicle wheel to which the balancing weight is to be fitted. In a typical balancing machine, when balancing the rotary member, it is necessary to rotate by hand the rotary member from the position where it stopped after the imbalance measuring run to the desired rotary angular position for the balancing operation which corresponds to the easy balancing position.